“Sherlock” Season 3 returns its title character to active duty and gives him a new enemy to face. But why is Sherlock Holmes “rusty,” according to Benedict Cumberbatch? How did Martin Freeman almost lose the part of Dr. John Watson? Who is the new bad guy, Charles Augustus Magnussen?

The answers are here. Watch out for “Sherlock” spoilers ahead!

Martin Freeman almost missed playing Watson

Freeman was having a bad day when he first auditioned for the role of John Watson on “Sherlock.” But at least the actor had a good reason — he had had his wallet stolen earlier that same day.

“I’ll admit maybe I was a bit stressed,” Freeman told Radio Times in an interview. “A week later, my agent rang and said, ‘List, this ‘Sherlock’ thing, they’re sort of under the impression you weren’t that into it.’ And I said, ‘Oh … I am really interested. Please call them and let them know that I am interested.’ I wasn’t being blase about it at all. I just wasn’t on my best day.”

Fortunately, the producers of “Sherlock” did bring in the actor for a second round of auditions. This time, he was paired with Cumberbatch. “I thought he was a fantastic actor,” Freeman said. “There was something about our rhythms, similarities and differences that meant that it just happened.”

Sherlock has been gone for a little too long

You thought the gap between Seasons 2 and 3 of “Sherlock” was long? It seems that Sherlock Holmes felt the same way. Cumberbatch revealed in an interview that Sherlock won’t be at the top of his game upon the detective’s return to London. “Sherlock has been away for two years and he’s rusty,” the actor told reporters recently. “His game’s just a little bit off. In this series, you find out a lot more about why he is the way he is.”

How do you follow Moriarty?

While Sherlock didn’t die at the end of Season 2, his foe, Moriarty, did. That means the show needs a new villain to antagonize Holmes and Watson throughout Season 3. Enter Charles Augustus Magnussen. Steven Moffat said in an interview that Magnussen is “the worst man in London” and “the Napoleon of blackmail.”

This “terrifying predator” will appear in the third episode of Season 3, “His Last Vow.” Sherlock tracks him during an investigation into some stolen letters. Unfortunately for the detective, Magnussen happens to know the deep, dark secrets of every important leader in the world. That makes him rather difficult to defeat.

“Sherlock” Season 3 premieres on Jan. 1 in the UK and Jan. 19 in the US.

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